1. Field of the Invention
The present invention relates to a plasma display apparatus, particularly to a plasma display apparatus having an improved chassis structure provided on the backside of a plasma display panel.
2. Description of the Related Prior Art
Recently, plasma display apparatus has been in spreading which is usually large in screen size and thin in thickness. Such a plasma display apparatus comprises a plasma display panel (hereinafter, simply referred to as PDP) including a pair of substrate plates arranged to face each other with an electric discharge space formed therebetween, a plurality of row electrodes and a plurality of column electrodes arranged orthogonal to the row electrodes, a plurality of electric discharge cells each formed at an intersection between a row electrode and a column electrode, so that a desired displaying can be achieved by effecting electric discharges in various discharge cells.
Further, such a plasma display apparatus has a chassis structure located on the backside of the PDP. The chassis structure is provided to support a PDP as well as a circuit board mounting a drive circuit for driving the PDP. In practice, such a chassis structure is required to function not only as support means, but also as cooling means for releasing a heat generated by the PDP so as to cool the PDP.
FIG. 4 is an explanatory view showing a chassis structure for use in a conventional plasma display apparatus. As shown in FIG. 4, PDP 1 has a glass substrate plate 1A and a glass substrate plate 1B, which are bonded together with an electric discharge space formed therebetween. A circuit board 2 mounting a drive circuit for driving the PDP 1 is mounted through a chassis structure 3 on the PDP 1.
Here, chassis structure 3 comprises a plurality of longitudinal members 3A and a plurality of lateral members 3B, thus forming a lattice arrangement. In practice, both the longitudinal and lateral members are all made of a metal such as aluminum having a high thermal conductivity. The circuit board 2 is electrically connected to the PDP 1 by means of a flexible cable 4. The chassis 3 and the PDP 1 are bonded together through a plurality of strip-like pressure sensitive adhesive double coated tapes 5, in a manner shown in FIG. 4.
However, when the above-described conventional chassis structure is required to have a sufficient strength for supporting the PDP 1, the only effective measure is to increase the thickness of both the longitudinal members 3A and the lateral members 3B. This, however, undesirably increases the total weight of the plasma display apparatus. Moreover, since the chassis structure involves a lattice arrangement, it will be difficult to perform an assembling operation to form the chassis structure, because the longitudinal and lateral members 3A and 3B having an increased thickness and an increased weight are relatively difficult to deal with. As a result, there has been a problem that the productivity is comparatively low.
In addition, as to the heat radiation of the conventional plasma display apparatus, since the lateral members 3B are arranged at an interval on the PDP 1, it is difficult for the whole apparatus to obtain a uniform radiation effect, thus making it impossible to ensure a sufficient each radiation.
On the other hand, with other conventional plasma display apparatus, a chassis structure is usually formed by performing a pressing treatment on a single plate so as to form several convex portions for attaching a circuit board. However, if the chassis structure is required to ensure an increased strength, the same measure would have to be taken in the same manner as described in the above, bringing about the same problems of increasing the total weight of the display apparatus as well as increasing the production cost.
An object of the present invention is to provide an improved plasma display apparatus which is light in weight and low in production cost, has a sufficient support strength and a sufficient heat radiation effect.
In a first aspect of the present invention, there is provided a plasma display apparatus including a plasma display panel, a circuit board mounting a drive circuit for driving the plasma display panel, a chassis structure provided on the backside of the plasma display panel for supporting the plasma display panel and for mounting the circuit board. In particular, the chassis structure comprises a first chassis member mounting the circuit board, and a second chassis member fixed on the backside of the plasma display panel, a plurality of support portions provided between the first and second chassis members for supporting the two chassis members and for forming a predetermined interval between the two chassis members.
In a second aspect of the present invention, the second chassis member""s one surface fixed on the backside of the plasma display panel is in a plain state, and is bonded on the backside of the plasma display panel.
In a third aspect of the present invention, the number of support portions located in central area is larger than that of support portions located in edge areas on the plasma display panel.
In a fourth aspect of the present invention, the plurality of support portions are projections formed on the first chassis member.
In a fifth aspect of the present invention, the plurality of projections are formed by carrying out a drawing treatment on the first chassis member.
According to the first aspect of the present invention, a chassis structure is provided to support a plasma display panel and a circuit board mounting a drive circuit for driving the plasma display panel. The chassis structure is comprised of a first chassis member and a second chassis member. A plurality of support portions are provided between the first and second chassis members for supporting the two chassis members and producing an interval between the two chassis members. In this way, by virtue of the interval and support portions, a total area for heat radiation has become larger than prior art, thereby making it possible to obtain an improved heat radiation effect. Further, since the chassis structure is formed by the first chassis member and the second chassis member, the second chassis member may be made by a material having a high thermal conductivity, while the first chassis member may be made by a highly processable material. Therefore, it is possible to obtain an improved chassis structure which has desired thermal conductive properties and is also suitable for production in a large quantity.
According to the second aspect of the present invention, the chassis structure is so formed that the second chassis member""s one surface fixed on the backside of the plasma display panel is in a plain state, and is bonded on the backside of the plasma display panel. In this way, a heat irradiation effect may be made uniform over the entire plasma display panel, thereby ensuring a uniform temperature distribution over the entire plasma display panel and thus alleviating an undesired heat stress.
According to the third aspect of the present invention, since the number of support portions located in central area is larger than that of support portions located in edge areas on the plasma display panel, the plasma display panel""s central area involving the largest amount of heat irradiation is allowed to have an improved heat irradiation through a relatively large numbers of the support portions.
According to the fourth and fifth aspects of the present invention, since the chassis structure comprises only the first chassis member and the second chassis member, and since the support portions located between the two chassis members are formed through a drawing treatment, it is possible to ensure that an attachment structure for combining together the first chassis member and the second chassis member can be held by the first chassis member which is located relatively far away from the plasma display panel, and that the second chassis member can be made flat. Therefore, it is allowed to ensure a uniform heat irradiation, and to reduce the number of parts forming the chassis structure, thus reducing the production cost. In addition, since a plurality of projections are formed as the support portions on the first chassis member, and are adhesively combined with the second chassis members, it is possible to make the chassis to be in a solid structure, thereby enabling the chassis structure to have an improved bending strength.